Method of processing target object

ABSTRACT

A method includes anisotropically etching an etching target layer of a target object through an opening of the target object by generating plasma of a first gas within a processing vessel in which the target object is accommodated; and then forming a film on an inner surface of the opening by repeating a sequence comprising: a first process of supplying a second gas into the processing vessel; a second process of purging a space within the processing vessel; a third process of generating plasma of a third gas containing an oxygen atom within the processing vessel; and a fourth process of purging the space within the processing vessel. The first gas contains a carbon atom and a fluorine atom. The second gas contains an aminosilane-based gas. The etching target layer is a hydrophilic insulating layer containing silicon. Plasma of the first gas is not generated in the first process.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Patent Application Nos.2017-082026 and 2018-046977 filed on Apr. 18, 2017 and Mar. 14, 2018,respectively, the entire disclosures of which are incorporated herein byreference.

TECHNICAL FIELD

The embodiments described herein pertain generally to a method ofprocessing a target object.

BACKGROUND

In a manufacturing process of an electronic device, a mask is formed ona target layer, and etching is performed to transfer a pattern of thecorresponding mask to the target layer. Patent Document 1 discloses atechnique of improving a shape of a hole of the pattern formed by theetching. Patent Document 2 discloses a technique for forming a recesspattern on a substrate successfully by etching and film forming. PatentDocument 3 discloses a technique of performing etching periodicallywhile forming a protective film of the mask.

Patent Document 1: International Publication No. WO2014/046083 pamphlet

Patent Document 2: Japanese Patent Laid-open Publication No. 2014-017438

Patent Document 3: Japanese Patent Laid-open Publication No. 2006-523030

SUMMARY

There is a demand for a technique of selectively forming a film on arequired region of a target object with high controllability.

In one example embodiment, there is provided a method of processing atarget object. The target object has an etching target layer and a maskprovided on the etching target layer. The mask is provided with anopening reaching the etching target layer. The method includesanisotropically etching the etching target layer through the opening(hereinafter, referred to as process a); and forming a film on an innersurface of the opening after performing the process a (hereinafter,referred to as process b). In the process a, plasma of a first gas isgenerated within a processing vessel of a plasma processing apparatus inwhich the target object is accommodated. In the process b, the film isformed on the inner surface of the opening by repeating a sequencecomprising: a first process of supplying a second gas into theprocessing vessel; a second process of purging a space within theprocessing vessel after the first process; a third process of generatingplasma of a third gas containing an oxygen atom within the processingvessel after the second process; and a fourth process of purging thespace within the processing vessel after the third process. The firstgas contains a carbon atom and a fluorine atom. The second gas containsan organic-containing aminosilane-based gas. The etching target layer isa hydrophilic insulating layer containing silicon. Plasma of the firstgas is not generated in the first process.

Through the etching performed in the process a, a deposit as a reactionproduct originated from the first gas is attached to the opening, and abowing shape (recess) may be formed at a portion of the inner surface ofthe opening where no deposit is attached (where the etching target layeris exposed). According to the method of the exemplary embodiment,through the process b performed after the process a, the depositadhering to the opening is removed, and a film is formed on the portionwhere the bowing shape is formed, so that the bowing shape can bereduced.

In the first process, the etching target layer is etched through theopening while a temperature of the target object is adjusted to beuniform across regions of the target object. In the first processingusing the second gas, since chemical reaction is made without generatingplasma, a thickness of the film formed through the process b includingthe first process is increased with a rise of a temperature of thetarget object (particularly, the etching target layer) on which the filmis formed. Accordingly, according to the method of the present exemplaryembodiment, the thickness of the film formed in the process b can beuniformed across multiple regions of the target object.

The processing vessel is provided with a first gas inlet opening and asecond gas inlet opening. The first gas inlet opening is provided abovethe target object. The second gas inlet opening is provided at a side ofthe target object. In the process a, the first gas is supplied into theprocessing vessel from the first gas inlet opening and a backflowprevention gas is supplied into the processing vessel from the secondgas inlet opening. In the first process of the process b, the second gasis supplied into the processing vessel from the second gas inlet openingand the backflow prevention gas is supplied into the processing vesselfrom the first gas inlet opening. In the third process of the process b,the third gas is supplied into the processing vessel from the first gasinlet opening and the backflow prevention gas is supplied into theprocessing vessel from the second gas inlet opening. A pipelineconnected to the first gas inlet opening and a pipeline connected to thesecond gas inlet opening are not intersected with each other. The secondgas inlet opening through which the second gas, which is used in thefirst process and contains the organic-containing aminosilane-based gashaving relatively high reactivity, is introduced into the processingvessel and the first gas inlet opening through which the first gas,which is used in the process a and contains the carbon atom and thefluorine atom, and the third gas, which is used in the third process andcontains the oxygen atom, are introduced into the processing vessel aredifferent from each other. Further, a gas supply line connected to thefirst gas inlet opening and a gas supply line connected to the secondgas inlet opening are not intersected with each other. Therefore, it ispossible to reduce the reaction product that might be originated fromthe second gas including the organic-containing aminosilane-based gashaving the relatively high reactivity and the first and third gases andthat might be generated within the gas supply lines. Furthermore, byusing the backflow prevention gas, it is possible to suppress any of thefirst gas, the second gas and the third gas from flowing back into thegas supply line in which any of the first gas, the second gas and thethird gas is not flowing.

The first gas includes a fluorocarbon-based gas. The etching upon theetching target layer made of the hydrophilic insulating layer containingthe silicon can be performed in the process a by using the first gascontaining the fluorocarbon-based gas.

The second gas includes monoaminosilane. The formation of the reactionprecursor of the silicon can be performed in the first process by usingthe second gas containing the monoaminosilane.

The aminosilane-based gas contained in the second gas includesaminosilane having 1 to 3 silicon atoms. The aminosilane-based gascontained in the second gas includes aminosilane having one to threeamino groups. As stated, the aminosilane having the one to three siliconatoms may be used as the aminosilane-based gas contained in the secondgas. Further, the aminosilane having the one to three amino groups maybe used as the aminosilane-based gas contained in the second gas.

In another exemplary embodiment, there is provided a method ofprocessing a target object. The method includes selectively forming afirst film on a surface of the target object; and forming a second filmon the surface of the target object by atomic layer deposition whileremoving the first film.

The deposition includes a sequence comprising: a first process ofsupplying a second gas into a processing vessel to form an adsorptionlayer on the surface of the target object; a second process of purging aspace within the processing vessel; and a third process of generatingplasma of a third gas within the processing vessel.

The deposition further comprises a fourth process of exposing the secondfilm to an inert gas plasma after the third process.

In the forming of the second film, the first film is removed through thethird process or the fourth process.

The second gas is any of an aminosilane-based gas, a silicon-containinggas, a titanium-containing gas, a hafnium-containing gas, atantalum-containing gas, a zirconium-containing gas and anorganic-containing gas, and the third gas is any of an oxygen-containinggas, a nitrogen-containing gas and a hydrogen-containing gas.

The first film is formed by plasma etching.

The plasma etching is atomic layer etching.

In still another exemplary embodiment, there is provided a method ofprocessing a target object. The method includes preparing a targetobject having a first region made of a first material and a secondregion made of a second material different from the first material;forming a first gas into plasma to etch the first region, therebyforming a first film on the second region; and forming a second film onthe first region by atomic layer deposition while removing the firstfilm.

The first gas includes a fluorocarbon gas, the first material includessilicon and oxygen, and the second material includes any of silicon, anorganic material and a metal.

The first gas includes a fluorohydrocarbon gas, the first materialincludes silicon and nitrogen, and the second material includes any ofsilicon, an organic material and a metal.

The second film contains silicon.

The second film formed on the target object has multiple filmthicknesses.

By repeating the sequence, the first film is removed and the second filmis formed on the surface of the target object from which the first filmis removed.

In accordance with the example embodiments, it is possible to provide atechnique capable of forming the film selectively on the required regionof the target object with high controllability.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description that follows, embodiments are described asillustrations only since various changes and modifications will becomeapparent to those skilled in the art from the following detaileddescription. The use of the same reference numbers in different figuresindicates similar or identical items.

FIG. 1 is a flowchart illustrating a method of processing a targetobject according to an exemplary embodiment;

FIG. 2 is a diagram illustrating an example of a plasma processingapparatus according to the exemplary embodiment which is used inperforming the method MT shown in FIG. 1;

FIG. 3 is a diagram schematically illustrating an example of a part ofmultiple regions of a main surface of the target object in the method ofprocessing the target object according to the exemplary embodiment;

FIG. 4A is a cross sectional view illustrating a state of the targetobject obtained before processes shown in FIG. 1 are performed, FIG. 4Bis a cross sectional view illustrating a state of the target objectobtained after etching shown in FIG. 1 is performed, and FIG. 4C is across sectional view illustrating a state of the target object obtainedafter a sequence shown in FIG. 1 is performed multiple times;

FIG. 5 is a diagram illustrating states of a supply of a gas and asupply of a high frequency power from a high frequency power supply inthe individual processes shown in FIG. 1;

FIG. 6A is a diagram schematically illustrating a state of the targetobject obtained before the sequence shown in FIG. 1 is performed, FIG.6B is a diagram schematically illustrating a state of the target objectobtained while the sequence shown in FIG. 1 is being performed, and FIG.6C is a diagram schematically illustrating a state of the target objectobtained after the sequence shown in FIG. 1 is performed;

FIG. 7 is a flowchart illustrating a method of processing a targetobject according to another exemplary embodiment;

FIG. 8A and FIG. 8B are diagrams schematically illustrating a state inwhich a film is being formed on a surface of the target object throughthe method shown in the flowchart of FIG. 7;

FIG. 9A and FIG. 9B are diagrams schematically illustrating etching andformation of a film through the method shown in the flowchart of FIG. 7;

FIG. 10 is a diagram illustrating a variation in a film thickness whilethe method shown in the flowchart of FIG. 7 is performed; and

FIG. 11 is a diagram illustrating a variation in a film thickness whilethe method shown in the flowchart of FIG. 7 is performed.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part of the description. In thedrawings, similar symbols typically identify similar components, unlesscontext dictates otherwise. Furthermore, unless otherwise noted, thedescription of each successive drawing may reference features from oneor more of the previous drawings to provide clearer context and a moresubstantive explanation of the current example embodiment. Still, theexample embodiments described in the detailed description, drawings, andclaims are not meant to be limiting. Other embodiments may be utilized,and other changes may be made, without departing from the spirit orscope of the subject matter presented herein. It will be readilyunderstood that the aspects of the present disclosure, as generallydescribed herein and illustrated in the drawings, may be arranged,substituted, combined, separated, and designed in a wide variety ofdifferent configurations, all of which are explicitly contemplatedherein.

Hereinafter, various exemplary embodiments will be described in detailwith reference to the accompanying drawings. In the various drawings,same or corresponding parts will be assigned same reference numerals.

First Exemplary Embodiment

If a target layer is etched by using a mask which defines a patternshape, a reaction product is deposited on an inner side surface of anopening (an opening of the mask) as the etching progresses. For thisreason, necking, that is, clogging of the opening due to the depositionof the reaction product may take place. If a deposit of the reactionproduct is formed in the opening, ions in plasma collide with thecorresponding deposit, and a travel direction of the ions is bent sothat anisotropy thereof is lost. Accordingly, the ions may collide withthe inner side surface of the opening and a bowing shape may be formedat a side surface thereof. If the bowing shape becomes conspicuous,inner sides of two neighboring openings may be penetrated. In thisregard, there is a demand for a technique capable of suppressing thebowing shape at the inner side surface of the opening which might becaused by the etching. A first exemplary embodiment provides a techniqueof suppressing the bowing shape, which may be caused by the etching, atthe inner side surface of the opening.

FIG. 1 is a flowchart for describing a method of processing a targetobject (hereinafter, referred to as “wafer W”) according to theexemplary embodiment. A method MT shown in FIG. 1 is an example of amethod of processing the target object. The method MT (the method ofprocessing the target object) is performed by a plasma processingapparatus 10.

FIG. 2 is a diagram illustrating an example of the plasma processingapparatus according to the exemplary embodiment which is used inperforming the method MT shown in FIG. 1. FIG. 2 schematicallyillustrates a cross sectional structure of the plasma processingapparatus 10 which can be used in various exemplary embodiments of themethod MT. As depicted in FIG. 2, the plasma processing apparatus 10 isconfigured as a plasma etching apparatus having parallel plate typeelectrodes, and is equipped with a processing vessel 12. The processingvessel 12 has a substantially cylindrical shape, and confines aprocessing space Sp. The processing vessel 12 is made of, by way ofexample, aluminum, and an inner wall surface thereof is anodicallyoxidized. The processing vessel 12 is frame-grounded.

A substantially cylindrical supporting member 14 is provided on a bottomportion of the processing vessel 12. The supporting member 14 is madeof, by way of example, but not limitation, an insulating material. Theinsulating material forming the supporting member 14 may contain oxygen,such as quartz. Within the processing vessel 12, the supporting member14 is vertically extended from the bottom portion of the processingvessel 12. Further, a mounting table PD is provided within theprocessing vessel 12. The mounting table PD is supported by thesupporting member 14.

The mounting table PD is configured to hold the wafer W on a top surfacethereof. A main surface FW of the wafer W is at the opposite side to arear surface of the wafer W which is in contact with the top surface ofthe mounting table PD, and faces the upper electrode 30. The mountingtable PD includes a lower electrode LE and an electrostatic chuck ESC.The lower electrode LE is provided with a first plate 18 a and a secondplate 18 b. The first plate 18 a and the second plate 18 b are made of ametal such as, but not limited to, aluminum and have a substantiallydisk shape. The second plate 18 b is provided on the first plate 18 a,and is electrically connected with the first plate 18 a.

The electrostatic chuck ESC is provided on the second plate 18 b. Theelectrostatic chuck ESC includes a pair of insulating layers orinsulating sheets; and an electrode embedded therebetween. The electrodeof the electrostatic chuck ESC is implemented by a conductive film, andelectrically connected to a DC power supply 22 via a switch 23. When thewafer W is placed on the mounting table PD, the wafer W is in contactwith the electrostatic chuck ESC. Specifically, the rear surface(opposite to the main surface FW) of the wafer W is in contact with theelectrostatic chuck ESC. The electrostatic chuck ESC is configured toattract the wafer W by an electrostatic force such as a Coulomb forcegenerated by a DC voltage applied from the DC power supply 22.Accordingly, the electrostatic chuck ESC is capable of holding the waferW.

A focus ring FR is provided on a peripheral portion of the second plate18 b to surround an edge of the wafer W and the electrostatic chuck ESC.The focus ring FR is configured to improve etching uniformity. The focusring FR is made of a material which is appropriately selected dependingon a material of an etching target film. For example, the focus ring FRmay be made of quartz.

A coolant path 24 is provided within the second plate 18 b. The coolantpath 24 constitutes a temperature control mechanism. A coolant issupplied into the coolant path 24 from a chiller unit (not shown)provided outside the processing vessel 12 via a pipeline 26 a. Thecoolant supplied into the coolant path 24 is then returned back into thechiller unit via a pipeline 26 b. In this way, the coolant is suppliedand circulated through the coolant path 24. A temperature of the wafer Wheld by the electrostatic chuck ESC can be controlled by adjusting atemperature of the coolant.

Furthermore, the plasma processing apparatus 10 is provided with a gassupply line 28. A heat transfer gas, e.g., a He gas, from a heattransfer gas supply device is supplied into a gap between a top surfaceof the electrostatic chuck ESC and the rear surface of the wafer Wthrough the gas supply line 28.

The plasma processing apparatus 10 is also equipped with a temperaturecontrol unit HT configured to adjust the temperature of the wafer W. Thetemperature control unit HT is embedded in the electrostatic chuck ESC,and is connected to a heater power supply HP. As a power is supplied tothe temperature control unit HT from the heater power supply HP, thetemperature of the electrostatic chuck ESC is adjusted, and, thus, thetemperature of the wafer W placed on the electrostatic chuck ESC isadjusted. Alternatively, the temperature control unit HT may be embeddedin the second plate 18 b.

The temperature control unit HT is equipped with a plurality of heatingelements each configured to generate heat; and a plurality oftemperature sensors respectively configured to detect temperaturesaround the plurality of heating elements. As depicted in FIG. 3, each ofthe plurality of heating elements is arranged to correspond to eachcorresponding one of multiple regions ER of the main surface FW of thewafer W when the wafer W is position-aligned on the electrostatic chuckESC. When the wafer W is position-aligned on the electrostatic chuckESC, a control unit Cnt recognizes the heating element and thetemperature sensor corresponding to each of the multiple regions ER ofthe main surface FW of the wafer W in relation with the correspondingregion ER. For each of the plurality of regions (regions ER), thecontrol unit Cnt is capable of identifying the region ER; and theheating element and the temperature sensor corresponding to the regionER based on a notation such as a number or a character. The control unitCnt detects a temperature of each region ER by the temperature sensorprovided at a position corresponding to the region ER and controls thetemperature of the region ER by the heating element provided at theposition corresponding to the region ER. Further, when the wafer W isplaced on the electrostatic chuck ESC, a temperature detected by asingle temperature sensor is equal to a temperature of the region ER ofthe wafer W where the corresponding temperature sensor is provided, and,referring to FIG. 4A, is equal to a temperature of the correspondingregion ER on the main surface FW of the wafer W and, more specifically,equal to a temperature of the mask MK and the etching target layer EL onthe corresponding region ER.

Further, the plasma processing apparatus 10 includes an upper electrode30. The upper electrode 30 is provided above the mounting table PD,facing the mounting table PD. The lower electrode LE and the upperelectrode 30 are arranged to be substantially parallel to each other andserve as parallel plate electrodes. Formed between the upper electrode30 and the lower electrode LE is the processing space Sp in which aplasma processing is performed on the wafer W.

The upper electrode 30 is supported at an upper portion of theprocessing vessel 12 with an insulating shield member 32 therebetween.The insulating shield member 32 is made of an insulating material, suchas quartz, containing oxygen. The upper electrode 30 may include anelectrode plate 34 and an electrode supporting body 36. The electrodeplate 34 faces the processing space Sp, and is provided with a multiplenumber of gas discharge holes 34 a. In the exemplary embodiment, theelectrode plate 34 contains silicon. In another exemplary embodiment,the electrode plate 34 may contain silicon oxide.

The electrode supporting body 36 is configured to support the electrodeplate 34 in a detachable manner, and is made of a conductive materialsuch as, but not limited to, aluminum. The electrode supporting body 36may have a water-cooling structure. A gas diffusion space 36 a is formedwithin the electrode supporting body 36. A multiple number of gasthrough holes 36 b are extended downwards from the gas diffusion space36 a, and these gas through holes 36 b respectively communicate with thegas discharge holes 34 a.

The plasma processing apparatus 10 further includes a first highfrequency power supply 62 and a second high frequency power supply 64.The first high frequency power supply 62 is configured to generate afirst high frequency power for plasma generation having a frequencyranging from 27 MHz to 100 MHz, e.g., 60 MHz. Further, the first highfrequency power supply 62 has a pulse specification and is controllablewithin a frequency ranging from 0.1 kHz to 50 kHz and a duty rangingfrom 5% to 100%. The first high frequency power supply 62 is connectedto the upper electrode 30 via a matching device 66. The matching device66 is a circuit configured to match an output impedance of the firsthigh frequency power supply 62 and an input impedance at a load side(lower electrode LE). Alternatively, the first high frequency powersupply 62 may be connected to the lower electrode LE via the matchingdevice 66.

The second high frequency power supply 64 is configured to generate asecond high frequency power for ion attraction into the wafer W, i.e., ahigh frequency bias power having a frequency ranging from 400 kHz to40.68 MHz. As an example, the second high frequency power supply 64generates the high frequency bias power having a frequency of 13.56 MHz.Further, the second high frequency power supply 64 has a pulsespecification and is controllable within a frequency ranging from 0.1kHz to 50 kHz and within a duty ranging from 5% to 100%. The second highfrequency power supply 64 is connected to the lower electrode LE via amatching device 68. The matching device 68 is a circuit configured tomatch an output impedance of the second high frequency power supply 64and the input impedance at the load side (lower electrode LE).

The plasma processing apparatus 10 further includes a power supply 70.The power supply 70 is connected to the upper electrode 30. The powersupply 70 is configured to apply, to the upper electrode 30, a voltagefor attracting positive ions existing in the processing space Sp intothe electrode plate 34. As an example, the power supply 70 is a DC powersupply configured to generate a negative DC voltage. If such a voltageis applied from the power supply 70 to the upper electrode 30, thepositive ions existing in the processing space Sp collide with theelectrode plate 34. Accordingly, secondary electrons and/or silicon maybe released from the electrode plate 34.

At the bottom portion of the processing vessel 12, a gas exhaust plate48 is provided between the supporting member 14 and a sidewall of theprocessing vessel 12. The gas exhaust plate 48 may be made of, by way ofexample, an aluminum member coated with ceramic such as Y₂O₃. Theprocessing vessel 12 is also provided with a gas exhaust opening 12 eunder the gas exhaust plate 48, and the gas exhaust opening 12 e isconnected with a gas exhaust device 50 via a gas exhaust line 52. Thegas exhaust device 50 has a vacuum pump such as a turbo molecular pump,and is capable of decompressing the space within the processing vessel12 to a required vacuum degree. A carry-in/out opening 12 g for thewafer W is provided at the sidewall of the processing vessel 12, and thecarry-in/out opening 12 g is opened/closed by a gate valve 54.

A gas source group 40 includes a plurality of gas sources. The pluralityof gas sources may include gas sources of various kinds of gases such asa source of an organic-containing aminosilane-based gas, a source of afluorocarbon-based gas (C_(x)F_(y) gas (x and y denote an integerranging from 1 to 10), a source of a gas (oxygen gas, etc.) having anoxygen atom and a source of an inert gas. As the organic-containingaminosilane-based gas, a gas having a molecular structure with arelatively small number of amino groups may be used. By way ofnon-limiting example, monoaminosilane (H₃—Si—R (R denotes an amino groupwhich contains an organic and may be substituted)) may be used. Theaforementioned organic-containing aminosilane-based gas (which iscontained in a second gas G1 to be described later) may includeaminosilane having one to three silicon atoms or aminosilane having oneto three amino groups. The aminosilane having the one to three siliconatoms may be monosilane (monoaminosilane) having one to three aminogroups, disilane having one to three amino groups, or trisilane havingone to three amino groups. Further, the aforementioned aminosilane mayhave an amino group which may be substituted. The amino group may besubstituted with any one of a methyl group, an ethyl group, a propylgroup or a butyl group. Furthermore, the aforementioned methyl group,the ethyl group, the propyl group or the butyl group may be substitutedwith a halogen. The fluorocarbon-based gas (a gas which is contained ina first gas to be described later) may be implemented by, by way ofexample, but not limitation, a CF₄ gas, a C₄F₆ gas, a C₄F₈ gas, or thelike. Further, the inert gas may be implemented by a nitrogen gas, an Argas, a He gas, or the like.

The valve group 42 includes a plurality of valves, and the flow ratecontrol unit group 44 includes a plurality of flow rate controllers suchas mass flow controllers. Each of the gas sources belonging to the gassource group 40 is connected to a gas supply line 38 and a gas supplyline 82 via a corresponding valve of the valve group 42 and acorresponding flow rate controller of the flow rate controller group 44.Accordingly, the plasma processing apparatus 10 is capable of supplyinga gas from one or more gas sources selected from the gas sourcesbelonging to the gas source group 40 into the processing vessel 12 at anindividually controlled flow rate.

Since the organic-containing aminosilane-based gas is supplied in theplasma processing apparatus 10 as will be described later, the plasmaprocessing apparatus 10 has a post mix structure in which a pipeline forsupplying the organic-containing aminosilane-based gas and a pipelinefor supplying another processing gas (e.g., an oxygen gas) areseparated. Since the organic-containing aminosilane-based gas has highreactivity, if the supply of the organic-containing aminosilane-basedgas and the supply of the other processing gas are performed through asame pipeline, a component of the organic-containing aminosilane-basedgas adhering to the inside of the pipeline may react with a component ofthe another processing gas, so that a reaction product generated by thisreaction may be deposited within the pipeline. The reaction productdeposited in the pipeline is difficult to remove by cleaning or thelike, which may cause particle generation and an abnormal discharge ifthe pipeline is located close to a plasma region. Thus, the supply ofthe organic-containing aminosilane-based gas and the supply of theanother processing gas may need to be separately performed throughindividual pipelines. In the post mix structure of the plasma processingapparatus 10, the organic-containing aminosilane-based gas and theanother processing gas are supplied through the separate pipelines.

The post mix structure of the plasma processing apparatus 10 includes atleast two pipelines (the gas supply line 38 and the gas supply line 82).The gas supply line 38 and the gas supply line 82 are connected with thegas source group 40 via the valve group 42 and the flow rate controllergroup 44.

The processing vessel 12 is provided with a gas inlet opening 36 c(first gas inlet opening). Within the processing vessel 12, the gasinlet opening 36 c is provided above the wafer W placed on the mountingtable PD. The gas inlet opening 36 c is connected to one end of the gassupply line 38. The other end of the gas supply line 38 is connected tothe valve group 42. The gas inlet opening 36 c is provided at theelectrode supporting body 36. Through the gas inlet opening 36 c, thefirst gas (containing the fluorocarbon-based gas) to be described later,a backflow prevention gas (containing the inert gas or the like) to bedescribed later, a third gas (containing an oxygen atom) to be describedlater and a purge gas (containing the inert gas or the like) to bedescribed later are introduced into the gas diffusion space 36 a. Thegases introduced into the processing space Sp from the gas inlet opening36 c through the gas diffusion space 36 a are supplied into a spaceabove the wafer W and between the wafer W and the upper electrode 30.

The processing vessel 12 is provided with a gas inlet opening 52 a(second gas inlet opening). Within the processing vessel 12, the gasinlet opening 52 a is provided at a lateral side of the wafer W placedon the mounting table PD. The gas inlet opening 52 a is connected to oneend of the gas supply line 82. The other end of the gas supply line 82is connected to the valve group 42. The gas inlet opening 52 a isprovided at the sidewall of the processing vessel 12. Through the gasinlet opening 52 a, a second gas G1 (containing the organic-containingaminosilane-based gas) to be described later and the backflow preventiongas (containing the inert gas or the like) are introduced into theprocessing space Sp. The gases introduced into the processing space Spfrom the gas into opening 52 a are supplied into the space above thewafer W and between the wafer W and the upper electrode 30.

The gas supply line 38 connected to the gas inlet opening 36 c and thegas supply line 82 connected to the gas inlet opening 52 a are notintersected with each other. That is, a supply path of the first gas andthe third gas including the gas inlet opening 36 c and the gas supplyline 38 and a supply path of the second gas G1 including the gas inletopening 52 a and the gas supply line 82 are not intersected with eachother.

In the plasma processing apparatus 10, a deposition shield 46 isprovided along an inner wall of the processing vessel 12 in a detachablemanner. The deposition shield 46 is also provided on an outer sidesurface of the supporting member 14. The deposition shield 46 isconfigured to suppress an etching byproduct (deposit) from adhering tothe processing vessel 12, and is formed by coating an aluminum memberwith ceramic such as Y₂O₃ or the like. Besides the Y₂O₃, the depositionshield may be made of an oxygen-containing material such as, but notlimited to, quartz.

The control unit Cnt is implemented by a computer including a processor,a storage unit, an input device, a display device, and so forth, and isconfigured to control individual components of the plasma processingapparatus 10 shown in FIG. 2. To elaborate, in the plasma processingapparatus 10, the control unit Cnt is connected to the valve group 42,the flow rate controller group 44, the gas exhaust device 50, the firsthigh frequency power supply 62, the matching device 66, the second highfrequency power supply 64, the matching device 68, the power supply 70,the heater power supply HP, the chiller unit, and so forth.

The control unit Cnt is operated to output control signals according toa computer program (a program based on an input recipe) for controllingthe individual components of the plasma processing apparatus 10 in therespective processes of the method MT. The individual components of theplasma processing apparatus 10 are controlled in response to the controlsignals from the control unit Cnt. To elaborate, in the plasmaprocessing apparatus 10 shown in FIG. 2, the selection of the gassupplied from the gas source group 40 and a flow rate of the selectedgas, the gas exhaust of the gas exhaust device 50, the power suppliesfrom the first and second high frequency power supplies 62 and 64, thevoltage application from the power supply 70, the power supply of theheater power supply HP, the control of the flow rate and the temperatureof the coolant from the chiller unit can be carried out in response tothe control signals from the control unit Cnt. Further, the individualprocesses of the method MT of processing the target object according tothe present exemplary embodiment can be performed by operating theindividual components of the plasma processing apparatus 10 under thecontrol of the control unit Cnt. The computer program for implementingthe method MT and various kinds of data used in performing the method MTare stored in the storage unit of the control unit Cnt in a retrievablemanner.

Referring back to FIG. 1, the method MT will be discussed in detail. Inthe following, an example where the plasma processing apparatus 10 isused to perform the method MT will be explained. In the followingdescription, reference is made to FIG. 4A to FIG. 6C. FIG. 4A is a crosssectional view illustrating a state of a target object obtained beforeprocesses shown in FIG. 1 are performed; FIG. 4B, a cross sectional viewillustrating a state of the target object obtained after etching shownin FIG. 1 is performed; and FIG. 4C, a cross sectional view illustratinga state of the target object obtained after a sequence shown in FIG. 1is performed multiple times. FIG. 5 is a diagram illustrating states ofthe supply of the gases and the supply of the high frequency powers inthe individual processes of the method MT shown in FIG. 1. FIG. 6A is adiagram schematically illustrating a state of the target object obtainedbefore the sequence shown in FIG. 1, for example, is performed; FIG. 6B,a diagram schematically illustrating a state of the target objectobtained while the sequence shown in FIG. 1 is being performed; and FIG.6C, a diagram schematically illustrating a state of the target objectobtained after the sequence shown in FIG. 1 is performed.

As depicted in FIG. 1, the method MT includes a process ST1, a sequenceSQ1 and a process ST3. Prior to performing the process ST1 of the methodMT, a wafer W as the target object is prepared. The prepared wafer Whas, as illustrated in FIG. 4A, an etching target layer EL and a maskMK. The mask MK is provided on a main surface ELa of the etching targetlayer EL. The mask MK is provided with an opening OP which reaches themain surface ELa of the etching target layer EL. The opening OP may be arecess, a hole, or the like. The main surface ELa of the etching targetlayer EL is partially exposed through the opening OP. The mask MK has aside surface MKa and a front surface MKb. The side surface MKa isincluded in an inner surface OPa of the opening OP. The front surfaceMKb is included in a main surface FW of the wafer W.

The etching target layer EL is made of a material selectively etchedagainst the mask MK. For example, a hydrophilic insulating layercontaining silicon may be used as the etching target layer EL. To bemore specific, the etching target layer EL may contain, by way ofnon-limiting example, silicon oxide (SiO₂). The etching target layer ELmay contain other materials such as silicon nitride Si₃N₄ orpolycrystalline silicon.

The mask MK is provided on the main surface ELa of the etching targetlayer EL. The mask MK is implemented by a resist mask containing aresist material such as ArF and is formed by patterning a resist layerthrough a photolithography technique. The mask MK partially covers themain surface ELa of the etching target layer EL. The opening OP definesa pattern shape of the mask MK. The pattern shape of the mask MK is, byway of example, but not limitation, a line-and-space pattern. Further,the mask MK may have a pattern which provides a circular opening whenviewed from the top. Alternatively, the mask MK may have a pattern whichprovides an elliptical opening when viewed from the top.

Prior to performing the process ST1, the wafer W shown in FIG. 4A isprepared, and the wafer W is accommodated within the processing vessel12 of the plasma processing apparatus 10 and placed on the mountingtable PD while being position-aligned thereon. While the method MT shownin FIG. 1 is being performed (at least while a process ST2 a included inthe method MT is being performed), the control unit Cnt detect atemperature of each of the multiple regions ER of the wafer W by thetemperature sensor of the temperature control unit HT provided at aposition corresponding to the region ER, and adjust the temperature ofthe region ER by the heating element of the temperature control unit HTprovided at the position corresponding to the region ER. As the controlunit Cnt performs this temperature control by using the temperaturecontrol unit HT, the temperature of the wafer W can be uniformed acrossthe multiple regions ER.

In the process ST1, the etching target layer EL of the wafer W shown inFIG. 4A is etched. In the process ST1, the etching target layer EL isanisotropically etched through the opening OP. In the process ST1,plasma of the first gas is generated within the processing space Sp ofthe processing vessel 12 of the plasma processing apparatus 10 in whichthe wafer W is accommodated. In the process ST1, from a gas sourceselected from the gas sources belonging to the gas source group 40, thefirst gas is supplied into the processing space Sp of the processingvessel 12 from the gas inlet opening 36 c through the gas supply line38, as indicated by a notation FG1 of FIG. 5. At the same time, thebackflow prevention gas is supplied into the processing space Sp of theprocessing vessel 12 from the gas inlet opening 52 a through the gassupply line 82, as indicated by a notation FG2 of FIG. 5. The first gasmay be selected depending on the material forming the etching targetlayer EL. The first gas contains a carbon atom and a fluorine atom. Byway of example, in case that the etching target layer EL is a siliconoxide film, the processing gas may contain a fluorocarbon-based gas. Thebackflow prevention gas is supplied into the processing space Sp fromthe gas inlet opening 52 a to suppress the first gas supplied into theprocessing space Sp and plasma ions of the first gas from beingintroduced into the gas supply line 82 through the gas inlet opening 52a. The backflow prevention gas may contain, by way of example, but notlimitation, an inert gas. Further, the high frequency power is suppliedfrom the first high frequency power supply 62, as indicated by anotation FG3 of FIG. 5. Further, the high frequency bias power issupplied from the second high frequency power supply 64, as indicated bya notation FG4 of FIG. 5. Further, by operating the gas exhaust device50, a pressure within the processing space Sp is set to a presetpressure. As a result, plasma is generated. Active species in thegenerated plasma etch the region of the main surface ELa of the etchingtarget layer EL exposed through the opening OP of the mask MK. Throughthe process ST1, the pattern (the pattern formed by the opening OP) ofthe mask MK is transcribed to the etching target layer EL, asillustrated in FIG. 4B.

Through the etching performed in the process ST1, the etching targetlayer EL is etched, and an inner side of the opening OP reaches theinside of the etching target layer EL. As shown in FIG. 4B, in theetching performed in the process ST1, the reaction product containingthe component included in the first gas is deposited on certain portionsof the front surface MKb of the mask MK and the side surface MKa of themask MK corresponding to the opening OP, and by this deposition, adeposit NC, which is the reaction product, is attached to the openingOP. That is, there occurs necking in which the opening OP is clogged dueto the deposition of the reaction product (adhesion of the deposit NC).The plasma ions generated in the process ST1 are incident upon the waferW vertically (anisotropically) with respect to the main surface FW ofthe wafer W. If the deposit NC is attached, however, the plasma ions areincident on the deposit NC to be collided with the deposit NC, so that atravel direction of the plasma ions is bent and anisotropy of the plasmaions disappears. Accordingly, the plasma ions collide with the innersurface OPa of the opening OP, so that the inner surface OPa of theopening OP becomes to have a bowing shape. Here, the inner surface OPaof the opening OP includes: of the inner side surface of the opening OP,the side surface MKa of the mask MK; of the inner side surface of theopening OP, a side surface ELb of the etching target layer EL; and, ofan inner bottom surface of the opening OP, a bottom surface ELc withinthe etching target layer EL (the same in the following description).

To perform a removal of the deposit NC attached to the opening OP in theprocess ST1 and a supplement of the bowing shape formed on the innersurface OPa of the opening OP in the process ST1, the sequence SQ1 andthe process ST3 following the process ST1 are performed multiple times.The sequence SQ1 and the process ST3 are a process of forming a film BFon the inner surface OPa of the opening OP after the process ST1 ofetching the etching target layer EL is performed.

After the process ST1, the sequence SQ1 is performed. The sequence SQ1includes a process ST2 a (first process), a process ST2 b (secondprocess), a process ST2 c (third process) and a process ST2 d (fourthprocess). In the method MT, the sequence SQ1 is repeated multiple times.As the sequence SQ1 is repeated multiple times through the sequence SQ1and the process ST3, the film BF is formed on the inner surface OPa ofthe opening OP. A series of processes from the start of the sequence SQ1to the process ST3 (YES) to be described later are a process ofconcurrently performing the removal of the deposit NC attached to theopening OP in the process ST1 and the supplement of the bowing shapeformed on the side surface MKa and the side surface ELb, and repairing ashape within the opening OP, more specifically, a shape of the innersurface OPa of the opening OP into a required shape. The supplement ofthe bowing shape formed on the side surface MKa and the side surface ELbis achieved by forming the film BF on a portion of the bowing shapeformed on the inner surface OPa of the opening OP. The film BF is asilicon oxide film containing silicon oxide (SiO₂).

In the process ST2 a, the second gas G1 from the gas supply line 82 issupplied into the processing space Sp of the processing vessel 12through the gas inlet opening 52 a, as indicated by a notation FG2 ofFIG. 5, and the backflow prevention gas from the gas supply line 38 issupplied into the processing space Sp of the processing vessel 12through the gas inlet opening 36 c, as indicated by a notation FG1 ofFIG. 5. The second gas G1 includes the organic-containingaminosilane-based gas. In the process ST2 a, the second gas G1 issupplied into the processing space Sp of the processing vessel 12 from agas source selected from the gas sources belonging to the gas sourcegroup 40. By way of non-limiting example, the organic-containingaminosilane-based gas such as monoaminosilane (H₃—Si—R (R denotes anamino group)) may be used as the second gas G1. In the process ST2 a,plasma of the second gas G1 is not generated, as indicated by notationsFG3 and FG4 of FIG. 5. Molecules (monoaminosilane) of the second gas G1adhere to the inner surface OPa of the opening OP (specifically, aportion of the inner surface OPa where the deposit NC is not attached)by chemical adsorption caused by chemical bond, and plasma is not usedin the process ST2 a. Furthermore, the second gas G1 may be any ofvarious other gases, besides the monoaminosilane, as long as moleculesthereof can be attached to the inner surface OPa (to be specific, theportion of the surface OPa where the deposit NC is not attached) bychemical bond and contains silicon. The backflow prevention gas issupplied into the processing space Sp from the gas inlet opening 36 c tosuppress the second gas G1 supplied into the processing space Sp frombeing introduced into the gas supply line 38 through the gas inletopening 36 c. The backflow prevention gas may include, by way ofnon-limiting example, an inert gas.

The reason why the monoaminosilane-based gas is selected as the secondgas G1 is because the chemical adsorption can be carried out relativelyeasily since the monoaminosilane has a molecular structure having arelatively high electro-negativity and polarity. As shown in FIG. 6A andFIG. 6B, a layer Ly1, which is formed as the molecules of the second gasG1 are attached to the inner surface OPa of the opening OP(specifically, a portion of the inner surface OPa which is exposed andon which no deposit NC is attached, the same for the surface OPa shownin FIG. 6A to FIG. 6C), becomes to have a state close a monomolecularlayer (monolayer) since the corresponding attachment is made by thechemical adsorption. The smaller the amino group R of themonoaminosilane is, the smaller the molecular structure of the moleculesadsorbed to the inner surface OPa of the opening OP is, so that sterichindrance which relies on the size of molecules is reduced. As a result,the molecules of the second gas G1 can be uniformly adsorbed onto theinner surface OPa of the opening OP, so that the layer Ly1 can be formedto have a uniform thickness across the inner surface OPa of the openingOP. By way of example, as the monoaminosilane (H₃—Si—R) contained in thesecond gas G1 reacts with a hydrophilic OH group of the inner surfaceOPa of the opening OP, H₃—Si—O as a reaction precursor is generated, sothat the layer Ly1 made up of a monomolecular layer of H₃—Si—O may beformed. Accordingly, the layer Ly1 of the reaction precursor can beconformally formed on the inner surface OPa of the opening OP. Further,since the deposit NC adhering to the opening OP includes a hydrophobiccompound containing a carbon atom and a fluorine atom, the layer Ly1 isnot formed on the deposit NC. However, as will be described later, thedeposit NC is physically removed by performing the sequence SQ1 multipletimes, and the layer Ly1 may be formed on the inner surface OPa of theopening OP which is exposed after the deposit NC is removed.

Furthermore, the aminosilane-based gas contained in the second gas G1may include, other than the monoaminosilane, aminosilane having one tothree silicon atoms. Alternatively, the aminosilane-based gas containedin the second gas G1 may include aminosilane having one to three aminogroups.

In the process ST2 a, the etching target layer EL is etched through theopening OP while the temperature of the wafer W is controlled to beuniform across the multiple regions ER of the wafer W. That is, whilethe process ST2 a is being performed, the control unit Cnt continuouslyperforms the temperature control upon the wafer W by using thetemperature control unit HT such that the temperature of the wafer W(particularly, the mask MK and the etching target layer EL of the waferW) is uniformed across the multiple regions ER. The degree of thechemical adhesion (chemical adsorption) of the molecules (e.g.,monoaminosilane) of the second gas G1 to the hydrophilic inner surfaceOPa of the opening OP depends on the temperature of the inner surfaceOPa. To elaborate, in case that the molecules (e.g., monoaminosilane) ofthe second gas G1 are chemically adsorbed to the hydrophilic innersurface OPa of the opening OP, a reaction rate of the chemicaladsorption is increased with a rise of the temperature of the surfaceOPa, as indicated by Arrhenius Equation which shows a correlationbetween a reaction rate of the chemical reaction and the temperature, sothat the number of the molecules of the second gas G1 chemicallyadsorbed to the corresponding inner surface OPa is increased. Thus, asthe temperature of the inner surface OPa is increased, a film thicknessof a layer Ly2 formed on the corresponding inner surface OPa isincreased, and a film thickness of the film BF formed on thecorresponding inner surface OPa is also increased by performing thesequence SQ1 multiple number of times. Thus, to form the film BF havinga uniform thickness across the multiple regions ER of the wafer W, it isrequired to perform, at least while the second process ST2 a is beingperformed, the temperature control upon the wafer W (particularly, themask MK and the etching target layer EL of the wafer W) continuouslysuch that the temperature of the wafer W (particularly, the mask MK andthe etching target layer EL of the wafer W) is uniformed across theentire multiple regions ER.

In the process ST2 b following the process ST2 a, the processing spaceSp of the processing vessel 12 is purged. To elaborate, the second gasG1 supplied in the process ST2 a is exhausted. By way of example, in theprocess ST2 b, an inert gas such as a nitrogen gas may be supplied intothe processing space Sp of the processing vessel 12 through the gassupply line 38 and the gas inlet opening 36 c as a purge gas. That is,the purging in the process ST2 b may be implemented by a gas purging ofallowing the inert gas to flow in the processing space Sp or a purgingby vacuum evacuation. In the process ST2 b, molecules excessivelyadhering to the inner surface OPa of the opening OP may be removed.Through the processes as stated above, the layer Ly1 of the reactionprecursor is formed to be a very thin monomolecular layer.

In the process ST2 c following the process ST2 b, plasma P1 of the thirdgas is generated within the processing vessel 12. In the process ST2 c,from a gas source selected from the gas sources belonging to the gassource group 40, the third gas containing the oxygen atom is suppliedinto the processing space Sp of the processing vessel 12 from the gasinlet opening 36 c through the gas supply line 38, as indicated by thenotation FG1 of FIG. 5. At the same time, the backflow prevention gas issupplied into the processing space Sp of the processing vessel 12 fromthe gas inlet opening 52 a through the gas supply line 82, as indicatedby the notation FG2 of FIG. 5. The third gas is a gas containing theoxygen atom and may be, by way of example, but not limitation, an oxygengas. The backflow prevention gas is supplied into the processing spaceSp from the gas inlet opening 52 a to suppress the third gas supplied inthe processing space Sp from being introduced into the gas supply line82 through the gas inlet opening 52 a. The backflow prevention gas mayinclude, by way of example, an inert gas. Further, as indicated by thenotation FG3 of FIG. 5, the high frequency power is supplied from thefirst high frequency power supply 62. In this case, the high frequencybias power from the second high frequency power supply 64 may also beapplied, as indicated by the notation FG4 of FIG. 5. Furthermore, it mayalso be possible to generate the plasma by using only the second highfrequency power supply 64 without using the first high frequency powersupply 62. By operating the gas exhaust device 50, the pressure of thespace within the processing space Sp is set to a preset pressure.

As stated above, the molecules (molecules constituting the monomolecularlayer of the layer Ly1) adhering to the inner surface OPa of the openingOP through the process ST2 a includes a bond between silicon andhydrogen. A binding energy of silicon and hydrogen is lower than that ofsilicon and oxygen. Accordingly, as illustrated in FIG. 6B, if theplasma P1 of the third gas containing the oxygen atom is generated,active species of the oxygen, for example, oxygen radicals aregenerated, and the hydrogen of the molecules constituting themonomolecular layer of the layer Ly1 is substituted with the oxygen, sothat the layer Ly2 of silicon oxide film (for example, a SiO₂ film) isformed as a monomolecular layer, as illustrated in FIG. 6C.

In the process ST2 d following the process ST2 c, the processing spaceSp of the processing vessel 12 is purged. To elaborate, the third gassupplied in the process ST2 c is exhausted. In the process ST2 d, aninert gas such as a nitrogen gas may be supplied into the processingspace Sp through the gas supply line 38 and the gas inlet opening 36 cas a purge gas. That is, the purging of the process ST2 d may beimplemented by the gas purging of allowing the inert gas to flow in theprocessing space Sp or the purging by vacuum evacuation.

In the above-described sequence SQ1, the purging is performed in theprocess ST2 b, and the hydrogen of the molecules constituting the layerLy1 is substituted with the oxygen in the process ST2 c following theprocess ST2 b. Accordingly, the same as in an atomic layer deposition(ALD) method, by performing the single cycle of the sequence SQ1, thelayer Ly2 of the silicon oxide film can be conformally formed in a thinuniform film thickness on the portion (including the bowing-shapedportion) of the inner surface OPa of the opening OP where no deposit NCis attached. In the present specification, the ALD refers to adeposition formed by atomic layer.

Since the deposit NC contains the hydrophobic compound having the carbonatom and the fluorine atom, the layer Ly1 is not formed on the depositNC. Single or multiple atomic layers of the deposit NC are removed froma surface of the deposit NC through the single cycle of the sequence SQL

In the process ST3 following the sequence SQ1, it is determined whetheror not to end the repetition of the sequence SQ1. To elaborate, in theprocess ST3, it is determined whether the repetition number of thesequence SQ1 has reached a predetermined number. Determining therepetition number of the sequence SQ1 is determining a thickness of thefilm BF shown in FIG. 4C. To be more specific, the thickness of the filmBF, which is formed on the portion (including the bowing-shaped portion)of the inner surface OPa of the opening OP where no deposit NC isattached, is determined by a product of the film thickness of thesilicon oxide film (layer Ly2) formed through the single cycle of thesequence SQ1 and the repetition number of the sequence SQ1. Accordingly,the repetition number of the sequence SQ1 is set based on the requiredthickness of the film BF formed on the portion (including thebowing-shaped portion) of the inner surface OPa of the opening OP whereno deposit NC is attached.

On a portion of the inner surface OPa of the opening OP where thedeposit NC is attached, the film BF is formed only by performing thesequence SQ1 after the side surface MKa and the side surface ELb areexposed by removing the deposit NC through the first cycle of thesequence SQ1 performed after the process ST1 or through multiple cyclesof the sequence SQ1 including the corresponding first cycle. If thedeposit NC having the hydrophobic surface (containing the compoundhaving the carbon atom and the fluorine atom) is removed through thefirst cycle of the sequence SQ1 performed after the process ST1 orthrough the multiple cycles of the sequence SQ1 including thecorresponding first cycle, the side surface MKa and the side surfaceELb, which are hydrophilic surfaces having the OH group, are exposed.Then, the monoaminosilane (H₃—Si—R) contained in the second gas G1reacts with the hydrophilic OH group in the inner surface OPa of theopening OP through the process ST2 a of the sequence SQ1 performed afterthe deposit NC is removed, so that the reaction precursor of the H₃—Si—Ois generated and the layer Ly1 as the monomolecular layer of the H₃—Si—Ois formed. The a repetition number of the sequence SQ1 until the film BFis formed on the portion of the inner surface OPa of the opening OPwhere the deposit NC is attached is smaller than the total repetitionnumber of the sequence SQ1. As a result, the film thickness of the filmBF formed on the portion of the inner surface OPa of the opening OPwhere the deposit NC is attached is smaller than the film thickness ofthe film BF formed on the portion (including the bowing-shaped portion)of the inner surface OPa of the opening OP where no deposit NC isattached.

If it is determined in the process ST3 that the repetition number of thesequence SQ1 has not reached the predetermined number (process ST3: NO),the sequence SQ1 is repeated. Meanwhile, if it is determined in theprocess ST3 that the repetition number of the sequence SQ1 has reachedthe predetermined number (process ST3: YES), the repetition of thesequence SQ1 is finished. As the sequence SQ1 is repeated thepredetermined number of times (process ST3: YES), the deposit NC isremoved, and the film BF of the silicon oxide film is formed on theinner surface OPa of the opening OP, as illustrated in FIG. 4C.

The film BF, which is formed on the portion of the inner surface OPa ofthe opening OP where no deposit NC is attached, is mainly formed on thebowing-shaped portion (recess within the opening OP) of the innersurface OPa of the opening OP. The film thickness of the film BF formedon the portion (including the bowing-shaped portion) of the innersurface OPa of the opening OP where no deposit NC is attached is largerthan the film thickness of the film BF formed on the portion of theinner surface OPa of the opening OP where the deposit NC is attached.Accordingly, by repeating the sequence SQ1 until it is determined in theprocess ST3 that the repetition number of the sequence SQ1 has reachedthe predetermined number, the bowing shape is supplemented by the filmBF, and the deposit NC attached to the opening OP is removed. Thus,through the method MT, the flatness of the inner surface OPa of theopening OP can be sufficiently recovered.

The method MT includes a sequence SQ2 and a process ST4. The sequenceSQ2 includes the aforementioned process ST1, the sequence SQ1 and theprocess ST3. In the method MT, the sequence SQ2 is performed one or moretimes. In the process ST4 following the sequence SQ2 (continued from theprocess ST3: YES), it is determined whether or not to finish therepetition of the sequence SQ2. To be specific, it is determined in theprocess ST4 that the repetition number of the sequence SQ2 has reachedthe predetermined number. If it is determined in the process ST4 thatthe repetition number of the sequence SQ2 has not reached thepredetermined number (process ST4: NO), the sequence SQ2 is repeated.Meanwhile, if it is determined in the process ST4 that the repetitionnumber of the sequence SQ2 has reached the predetermined number (processST4: YES), the repetition of the sequence SQ2 is finished. As thesequence SQ2 is repeated in this way, a depth of the inside of theopening OP can be adjusted to a required depth while maintaining theflatness and the shape of the inside of the opening OP.

Through the etching performed in the process ST1, the deposit NC as thereaction product originated from the first gas may be attached to theopening OP, and the bowing shape (recess) may be formed at the portionof the inner surface OPa of the opening OP where no deposit NC isattached (where the etching target layer EL is exposed). According tothe method MT of the exemplary embodiment described so far, through thesequence SQ1 and the process ST3 performed after the process ST1, thedeposit NC adhering to the opening OP is removed, and the bowing shapecan be reduced (improved) as the film BF is formed on the portion wherethe bowing shape is formed.

Furthermore, in the process ST2 a using the second gas, the chemicalreaction is made without generating the plasma. Thus, the thickness ofthe film BF formed through the sequence SQ1 including the process ST2 aand the process ST3 is increased with a rise of the temperature of thewafer W (particularly, the etching target layer EL) on which the film BFis formed. Therefore, according to the method MT, the thickness of thefilm BF formed in the sequence SQ1 and the process ST3 can be made to beuniform across the multiple regions ER of the wafer W.

Moreover, the gas inlet opening 52 a through which the second gas, whichis used in the process ST2 a and contains the organic-containingaminosilane-based gas having relatively high reactivity, is introducedinto the processing vessel 12 and the gas inlet opening 36 c throughwhich the first gas, which is used in the process ST1 and contains thecarbon atom and the fluorine atom, and the third gas, which is used inthe process ST2 c and contains the oxygen atom, are introduced into theprocessing vessel 12 are different from each other. Further, the gassupply line 38 connected to the gas inlet opening 36 c and the gassupply line 82 connected to the gas inlet opening 52 a are notintersected with each other. Therefore, it is possible to reduce areaction product that might be originated from the second gas includingthe organic-containing aminosilane-based gas having the relatively highreactivity and the first and third gases and might be generated withinthe gas supply lines (the gas inlet opening 36 c and the gas inletopening 52 a). Furthermore, by using the backflow prevention gas, it ispossible to suppress any of the first gas, the second gas and the thirdgas from flowing back into the gas supply line (the gas inlet opening 36c or the gas inlet opening 52 a) in which any of the first gas, thesecond gas and the third gas is not flowing.

Furthermore, the etching upon the etching target layer EL made of thehydrophilic insulating layer containing the silicon can be performed inthe process ST1 by using the first gas containing the fluorocarbon-basedgas, and the formation of the reaction precursor of the silicon can beperformed in the process ST2 a by using the second gas containing themonoaminosilane.

As stated above, according to the first exemplary embodiment, it ispossible to reduce the bowing shape on the side surface of the recesscaused by the etching.

Second Exemplary Embodiment

Now, the following description refers to FIG. 7 to FIG. 11. FIG. 7 is aflowchart illustrating a method MT of processing a wafer W according toa second exemplary embodiment. The method MT includes a process ST1 aand a process ST5 which are performed in sequence. The method MT mayfurther include a process ST1 b after the process ST1 a. In the secondexemplary embodiment, a surface of the wafer W includes a surface SFa ofa first region La of the wafer W and a surface SFb of a second region Lbof the wafer W. In this exemplary embodiment, a first film M1 is formedon the surface SFa of the first region La of the wafer W. A film isformed on the surface SFb of the second region Lb by ALD.

The control unit Cnt of the plasma processing apparatus 10 performs themethod MT by controlling the individual components of the plasmaprocessing apparatus 10.

FIG. 8A and FIG. 8B are cross sectional views illustrating states of thewafer W after the individual processes of the method MT shown in FIG. 7are performed. TM1 in FIG. 8A shows a state of the wafer at a momentwhen the process ST5 is begun, and TM2 in FIG. 8B shows a state of thewafer at a moment when the process ST5 is ended (particularly, removalof the first film M1 is ended) (the same in the description of FIG. 9Ato FIG. 11).

FIG. 9A and FIG. 9B schematically illustrate the removal of the firstfilm M1 and formation of a second film M2 according to the method MTshown in FIG. 7. FIG. 9A schematically illustrates the removal of thefirst film M1 and the formation of the second film M2 on the firstregion La. FIG. 9B schematically illustrates the formation of the secondfilm M2 on the second region Lb. FIG. 10 shows a thickness variation ofthe first film M1 and a thickness variation of the second film M2according to the method MT shown in FIG. 7. FIG. 11 shows differentthickness variations according to the method MT. A vertical axis of FIG.10 indicates the thickness of the first film M1. A vertical axis of FIG.11 represents the thickness of the second film M2. A horizontal axis ineach of FIG. 10 and FIG. 11 indicates a time elapsed from the beginningof a processing.

The method MT shown in FIG. 7 will be explained. The process ST1 a formsthe first film M1 (FIG. 8A) selectively on the wafer W. To elaborate, inthe process ST1 a, the first film M1 is formed on the surface SFa of thefirst region La of the wafer W, as illustrated in FIG. 8A. Here, thefirst film M1 is not formed on the surface SFb of the second region Lbof the wafer W (corresponding to a case shown in FIG. 10) or is formedthereon in a thickness smaller than a thickness of the first film M1formed on the surface SFa (corresponding to a case shown in FIG. 11).Further, the process ST1 a includes preparing the wafer W having thefirst region La made of a first material and the second region Lb madeof a second material different from the first material. The firstmaterial and the second material will be described later.

In the process ST1 a, the first film M1 is formed by using a fourth gas.The first film M1 may be formed by plasma enhanced chemical vapordeposition (PECVD) or thermal CVD using the fourth gas. As anotherexample, the first film M1 may be formed by etching with active speciesof the fourth gas. If the first material of the first region Lacontains, for example, any of silicon, an organic material and a metaland the second material of the second region Lb contains, for example,silicon and oxygen, the fourth gas may be a fluorocarbon gas. If thefirst material of the first region La contains, for example, any ofsilicon, an organic material and a metal and the second material of thesecond region Lb contains, for example, silicon and nitrogen, the fourthgas may be a fluorohydrocarbon gas. In this way, the fourth gas is a gashaving deposition property.

If the second region Lb is made of SiO₂, the first film M1 is formed onthe first region La by plasma etching with a gas such as C₄F₆.Meanwhile, if the second region Lb is made of SiN, the first film M1 isformed on the first region La by plasma etching with a gas such as CH₃F.

Now, an example of forming the first film M1 by the plasma etching willbe explained. According to this example, a thickness difference betweenthe first film M1 formed on the first region La and the first film M1formed on the second region Lb can be further increased. The process ST1a includes a fifth process and a sixth process. The fifth process andthe sixth process are performed in the plasma processing apparatus 10.In the process ST1 a, through the fifth process and the sixth process,the second region Lb is etched by using plasma of the fourth gas, andthe first film M1 is formed on the first region La.

First, the plasma of the fourth gas is generated within the processingvessel 12 in which the wafer W is accommodated, and a film is depositedon the surface SFa of the first region La and on the surface SFb of thesecond region Lb (fifth process). The fifth process includes adjusting apressure by supplying the fourth gas into the processing vessel 12.Then, the first high frequency power supply 62 is operated to apply thehigh frequency power, so that the plasma of the fourth gas is generated.In the fifth process, a high frequency power for ion attraction into thewafer W is not applied, or a power not causing etching is applied.Accordingly, the film is formed on the surface SFa of the first regionLa and the surface SFb of the second region Lb.

Subsequently, in the sixth process, the second region Lb is removed. Inthe sixth process, an inert gas is supplied into the processing vessel12. By operating the first high frequency power supply 62, the highfrequency power is supplied, and plasma of the inert gas is generated.In this sixth process, the high frequency power may be applied byoperating the second high frequency power supply 64. As a result, ionsof the inert gas are attracted into the film deposited in the fifthprocess. As the deposited film and a part of the second region Lb reactwith each other, the part of the second region Lb is removed. In thisetching, 1 to 10 atomic layers of the second region Lb are etched(referred to as pseudo-ALE) per a single cycle including the fifthprocess and the sixth process. Meanwhile, as for a reaction between thedeposited film and the first region La, it is difficult to generate areaction product having high volatility. Thus, the first region La isdifficult to remove as compared to the second region Lb. For thisreason, the first film M1 is formed on the first region La. The fifthprocess and the sixth process are repeated until an etching amount ofthe second region Lb reaches a preset amount. Upon the completion ofthis etching, the film is completely or mostly removed from the secondfilm Lb. This etching method improves selectivity for a depositionamount of the first film M1. Here, though the pseudo-ALE is used as anexample of forming the first film by etching, the second region Lb maybe etched by another method and the first film M1 may be formed on thefirst region La.

In the present exemplary embodiment, the first region La has the firstmaterial containing any of silicon, an organic material and a metal. Tobe specific, the first material of the first region La may by any oneof, by way of non-limiting example, Si, SiGe, Ge, SiN, SiC, an organicfilm, a metal (W, Ti, or the like), SiON and SiOC, or a combination ofany two or more thereof. The second region Lb includes the secondmaterial different from the first material forming the first region La,and may contain silicon and oxygen. To be more specific, the secondregion Lb has the second material containing SiO₂, SiON, SiOC, or thelike. The fourth gas may be a fluorocarbon-based gas such C₄F₆ or C₄F₈.The fourth gas may further contain an inert gas. The inert gas used inthe sixth process may include a rare gas such as an argon gas.

Further, as another example, the first region La may contain any ofsilicon, an organic material and a metal, and the second region Lb maycontain silicon and nitrogen. To be specific, the first region La maycontain any of, by way of non-limiting example, Si, SiO₂, SiC, anorganic film, a metal (W, Ti, or the like), SiON and SiOC, and thesecond region Lb may contain any of SiN, SiON, and so forth. In thisexample, the fourth gas may be any of various fluorohydrocarbon-basedgases. The fourth gas may further contain an inert gas. The inert gasused in the sixth process may include a rare gas such as an argon gas.

Now, reference is made back to FIG. 7. The process ST5 is a process offorming the second film M2 by ALD on the second region Lb while removingthe first film M1. In this way, in the process ST5, the second film M2(see FIG. 8B) is selectively formed on the surface of the wafer W byALD. The process ST5 includes a plasma processing, and the first film M1on the first region La is removed through repetition of thecorresponding plasma processing.

In the process ST5 of forming the second film M2, a total processingtime of the process ST2 c may be adjusted depending on a preset targetvalue of the thickness of the second film M2.

The process ST5 includes the sequence SQ1 and the process ST3. Thesequence SQ1 includes the process ST2 a, the process ST2 b, the processST2 c and, selectively, the process ST2 d. The sequence SQ1 mayselectively include a process ST2 e after the process ST2 d. The processST2 e is a process of generating plasma of an inert gas. Accordingly,the process ST2 e densifies the second film M2 formed through theprocess ST2 a, the process ST2 b, the process ST2 c and the process ST2d. Further, the thickness of the first film M1 may be adjusted throughthe process ST2 e. Processing times of the process ST2 c and the processST2 e can be adjusted individually.

The process ST1 a and the process ST5 can be performed continuously inthe same plasma processing apparatus 10 without breaking a vacuum state.Meanwhile, the process ST1 a and the process ST5 may be performed indifferent plasma processing apparatuses. In case that the process ST1 aand the process ST5 are performed in the different plasma processingapparatuses, the first film M1 is selectively formed in the process ST1a in one plasma processing apparatus. Then, in the process ST5, in theother plasma processing apparatus 10 different from the one plasmaprocessing apparatus, the second film M2 is selectively formed by theALD method on the exposed surface of the wafer W having the first filmM1 selectively formed thereon. The first film M1 on the first region Lais removed while the second film M2 is being formed by repeating thesequence SQ1. To elaborate, plasma of a modification gas in the processST2 c or plasma of the inert gas in the process ST2 e selectivelyperformed removes the first film M1 on the first region La. The removalamount of the first film can be controlled by adjusting the processingtime of the process ST2 c and the value of the first or second highfrequency power in the process ST2 c.

The second gas G1 (precursor gas) used in the process ST2 a is a gaswhich is adsorbed to a region of the wafer W where the first film M1 isnot formed (the first film M1 hampers adsorption of the second gas), andwhich forms an adsorption layer (layer Ly1 shown in FIG. 6A to FIG. 6C).The second gas G1 may be an aminosilane-based gas, a silicon-containinggas, a titanium-containing, a hafnium-containing gas, atantalum-containing gas, a zirconium-containing gas, or anorganic-containing gas. The third gas used in the process ST2 c is a gaswhich modifies the adsorption layer, and may be, by way of example, butnot limitation, an oxygen-containing gas, a nitrogen-containing gas or ahydrogen-containing gas.

To elaborate, an O₂ gas, a CO₂ gas, a NO gas, a SO₂ gas, a N₂ gas, a H₂gas, a NH₃ gas, or the like may be used as the third gas. Further, anozone gas (O₃ gas) may also be used as the third gas, and plasma neednot be generated in the process ST2 c.

FIG. 8A to FIG. 11 illustrate the processing performed in the processST5. As depicted in FIG. 8A and FIG. 10, the first film M1 isselectively formed on the surface SFa of the first region La in theprocess ST1 a. The wafer W has the first regions La. The first film M1is selectively formed on the first regions. In the exemplary embodiment,the first films M1 may have different thicknesses on the individualfirst regions.

A line LP1 and a line LP2 shown in FIG. 10 indicate a variation of thethickness of the first film M1 formed on the surface SFa of the firstregion La. A line LP3 shown in FIG. 10 indicates a variation of thethickness of the second film M2 formed on the surface SFb of the secondregion Lb. A line LP4 shown in FIG. 10 indicates a variation of thethickness of the second film M2 formed on the surface SFa when theprocess ST5 of forming the second film M2 is continuously performedafter the first film M1 is removed from the surface SFa of the firstregion La.

On the surface SFb of the second region Lb, the first film M1 is notformed through the process ST1 a, as illustrated in FIG. 8A and FIG. 10,or the first film M1 is formed in a thickness smaller than that of thefirst film M1 formed on the surface SFa, as illustrated in FIG. 8A andFIG. 11.

A line LP1 a and a line LP2 a shown in FIG. 11 indicate a variation ofthe thickness of the first film M1 formed on the surface SFb of thesecond region Lb in case that the first film M1 is formed on the surfaceSFb.

As illustrated in FIG. 9A, FIG. 9B, FIG. 10 and FIG. 11, if the processST5 is begun at a timing TM1, the first film M1 is removed stage bystage as the process ST5 is repeated (the line LP2 of FIG. 10, and theline LP2 and the line LP2 a of FIG. 11). Meanwhile, as the process ST5is repeated, the second film M2 are formed by atomic layer on thesurface SFb of the second region Lb where the first film M1 is notformed or on the surface SFb of the second region Lb from which thefirst film M1 is removed (the lines LP3 of FIG. 10 and FIG. 11).

In the exemplary embodiment, the process ST5 may be performedcontinuously from the timing TM1 to a timing TM2 when the first film M1on the surface SFa of the first region La is completely removed. FIG. 9Aand FIG. 9B illustrate an example where the process ST5 is repeatedthree times. That is, FIG. 9A and FIG. 9B illustrate the example theentire first film M1 on the first region La is removed as the processST5 is repeated three times.

At the moment when the process ST5 is first performed at the timing TM1,the surface SFb of the second region Lb is exposed, but the surface SFaof the first region La is not exposed by being covered with the firstfilm M1. As the process ST5 is first performed at the timing TM1, a partof the first film M1 covering the first region La is removed. The secondfilm M2 of a single atomic layer is formed on the exposed second regionLb.

Then, as the process ST5 is performed the second time, a part of thefirst film M1 on the first region La is further removed, and another oneatomic layer is formed on the second film M2 on the second region Lb, sothat the second film M2 of two atomic layers is formed. Subsequently, asthe process ST5 is performed the third time, the first film M1 on thefirst region La is completely removed, and another one atomic layer isformed on the second film M2 on the second region Lb, so that the secondfilm M2 of three atomic layers is formed. As stated, at the timing TM2when the repetition of the process ST5 is performed three times, theentire first film M1 on the first region La is removed, so that thesurface SFa of the first region La is exposed, and the second film M2having the three atomic layers is formed on the second region Lb.

As illustrated in FIG. 9A, FIG. 9B, FIG. 10, and FIG. 11, the processST5 may be continuously performed from the timing TM1 to the timing TM2when the entire first film M1 on the surface SFa of the first region Lais removed, but not limited thereto. In another exemplary embodiment,the process ST5 may be performed continuously until the first film M1 orthe second film M2 reaches a predetermined thickness. By way of example,the process ST5 may be performed even after the timing TM2 when thefirst film M1 on the surface SFa is completely removed. In this case, asthe process ST5 is performed every single time, the second film M2 isformed on the (exposed) surface SFa of the first region La by everysingle atomic layer and on the second region Lb by every single atomiclayer, as shown in FIG. 9A and FIG. 9B after the timing TM2 and as shownby the lines LP4 in FIG. 10 and FIG. 11.

FIG. 9A and FIG. 9B illustrate the example where the process ST5 isrepeated three times (cycles) after the timing TM2. As the process ST5is repeated three times after the timing TM2, the second film M2 havingthree atomic layers is formed on the first region La, and the secondfilm M2 having six atomic layers is formed on the second region Lb.

In the exemplary embodiment, the first film M1 is formed to havedifferent thicknesses on different regions of the wafer W. As the ALDcycle is repeated, the second film M2 is formed to have differentthicknesses on the different regions. That is, the second film M2 may beformed to have multiple thicknesses based on the multiple thicknesses ofthe first film M1.

Several specific examples of processing conditions that can be used inthe process ST1 a, the process ST2 a and the process ST2 c are specifiedin experimental examples 1 to 3 as follows.

Experimental Example 1

-   -   Material of the first region La: SiN    -   Material of the second region Lb: SiO₂

<Process ST1 a>

-   -   Internal pressure of the processing space Sp: 20 mTorr    -   Power from the first high frequency power supply 62: 500 W    -   Power from the second high frequency power supply 64: 0 W    -   Flow rate of the first gas: C₄F₆ gas (15 sccm)/Ar gas (350        sccm)/O₂ gas (20 sccm)    -   Temperature of the wafer W: 200° C.    -   Processing time: 10 sec    -   The first film M1 formed in this Example 1 is a fluorocarbon        film.

<Process ST2 a>

-   -   Internal pressure of the processing space Sp: 100 mTorr    -   Power from the first high frequency power supply 62: 0 W    -   Power from the second high frequency power supply 64: 0 W    -   Flow rate of first gas: aminosilane-based gas (50 sccm)    -   Temperature of the wafer W: 80° C.    -   Processing time: 15 sec

Experimental Example 2

-   -   Material of the first region La: SiN    -   Material of the second region Lb: SiO₂

<Process ST1 a>

-   -   The etching processing using the fifth process and the sixth        process is performed.    -   Repetition number of the fifth process and the sixth process: 2        times (twice)    -   The first film M1 formed in this Example 2 is a fluorocarbon        film.

<Fifth Process>

-   -   Internal pressure of the processing space Sp: 30 mTorr    -   Power from the first high frequency power supply 62: 100 W    -   Power from the second high frequency power supply 64: 0 W    -   Voltage from the DC power supply 70: −300 V    -   Flow rate of the fourth gas: C₄F₆ gas (16 sccm)/Ar gas (1000        sccm)/O₂ gas (10 sccm)    -   Processing time: 3 sec

<Sixth Process>

-   -   Internal pressure of the processing space Sp: 30 mTorr    -   Power from the first high frequency power supply 62: 500 W    -   Power from the second high frequency power supply 64: 0 W    -   Voltage from the DC power supply 70: −300 V    -   Flow rate of the fourth gas: C₄F₆ gas (0 sccm)/Ar gas (1000        sccm)/O₂ gas (0 sccm)    -   Processing time: 5 sec

<Process ST2 a>

-   -   Internal pressure of the processing space Sp: 100 mTorr    -   Power from the first high frequency power supply 62: 0 W    -   Power from the second high frequency power supply 64: 0 W    -   Flow rate of the first gas: aminosilane-based gas (50 sccm)    -   Temperature of the wafer W: 80° C.    -   Processing time: 15 sec

<Process ST2 c>

-   -   Internal pressure of the processing space Sp: 200 mTorr    -   Power from the first high frequency power supply 62 (frequency:        60 MHz): 500 W    -   Power from the second high frequency power supply 64 (frequency:        10 kHz): 300 W    -   Flow rate of the first gas: CO₂ gas (300 sccm)    -   Processing time: 5 sec

Experimental Example 3

-   -   Material of the first region La: SiN    -   Material of the second region Lb: SiO₂

<Process ST1 a>

-   -   The etching processing using the fifth process and the sixth        process is performed.    -   Repetition number of the fifth process to the sixth process: 2        times (twice)    -   The first film M1 formed in this Example 3 is a fluorocarbon        film.

<Fifth Process>

-   -   Internal pressure of the processing space Sp: 30 mTorr    -   Power from the first high frequency power supply 62: 100 W    -   Power from the second high frequency power supply 64: 0 W    -   Voltage from the DC power supply 70: −300 V (this condition can        be omitted)    -   Flow rate of the fourth gas: C₄F₆ gas (16 sccm)/Ar gas (1000        sccm)/O₂ gas (10 sccm)

Processing time: 3 sec

<Sixth Process>

-   -   Internal pressure of the processing space Sp: 30 mTorr    -   Power from the first high frequency power supply 62: 500 W    -   Power from the second high frequency power supply 64: 0 W    -   Voltage from the DC power supply 70: −300 V    -   Flow rate of the fourth gas: C₄F₆ gas (0 sccm)/Ar gas (1000        sccm)/O₂ gas (0 sccm)    -   Processing time: 5 sec

<Process ST2 a>

-   -   Internal pressure of the processing space Sp: 100 mTorr    -   Power from the first high frequency power supply 62: 0 W    -   Power from the second high frequency power supply 64: 0 W    -   Flow rate of the first gas: aminosilane-based gas (50 sccm)    -   Temperature of the wafer W: 80° C.    -   Processing time: 15 sec

<Process ST2 c>

-   -   Internal pressure of the processing space Sp: 200 mTorr    -   Power from the first high frequency power supply 62 (frequency:        60 MHz): 500 W    -   Power from the second high frequency power supply 64 (frequency:        10 kHz): 300 W    -   Flow rate of the first gas: CO₂ gas (300 sccm)    -   Processing time: 2 sec

The experimental example 2 and the experimental example 3 are differentin the processing times of the process ST2 c. The processing time (2sec) of the process ST2 c in the experimental example 3 is 2/5 times theprocessing time (5 sec) of the process ST2 c in the experimental example2. In this case, a removal rate of the first film M1 on the surface SFaof the first region La in the experimental example 3 equals to about 2/5times the removal rate in the experimental example 2.

Furthermore, the surface of the wafer W may be cleaned after the processST1 a and before the process ST5 (process ST1 b). The process ST1 b maybe performed in case that the first film M1 is formed on the secondregion Lb to remove the first film M1 from the second region Lb. Thesecond film M2 is not formed on the second region Lb from the beginningof the ALD process ST5 until the time when the first film M1 on thesecond region Lb is completely removed. The second film M2 starts to beformed after the first film M1 is removed from the second region Lb.Thus, by performing the cleaning of the process ST1 b, the formation ofthe second film M2 can be begun from the beginning of the process ST5.Therefore, the repetition number of the process ST5 required to allowthe second film M2 to reach a required thickness can be reduced.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting. The scope of the inventive concept is defined by thefollowing claims and their equivalents rather than by the detaileddescription of the exemplary embodiments. It shall be understood thatall modifications and embodiments conceived from the meaning and scopeof the claims and their equivalents are included in the scope of theinventive concept.

Other aspects according to the exemplary embodiments include Remarks 1to 4 as follows.

(Remark 1) A method of processing a target object, comprising: providingthe target object having a first film being selectively formed on asurface of the target object, forming a second film by atomic layerdeposition (ALD) on the surface of the target object while removing thefirst film.

(Remark 2)

A method of processing a target object, comprising: forming a first filmselectively on a first region of the target object; forming a firstatomic-layer-deposited film (ALD film) on a second region of the targetobject where the first film is not formed; and forming a second ALD filmon the first region after the first film on the first region is removedby repeating the ALD.

(Remark 3)

The method of Remark 2 in which the first ALD film is thicker than thesecond ALD film.

(Remark 4)

A method of processing a target object, comprising: preparing the targetobject having a first region made of a first material and a secondregion made of a second material different from the first material;etching the first region with plasma of a first gas to form a first filmon the second region; and forming a second film on the first region byALD while removing the first film.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting, with the true scope and spirit being indicated by thefollowing claims.

We claim:
 1. A method of processing a target object, the target objecthaving an etching target layer and a mask provided on the etching targetlayer, the mask being provided with an opening reaching the etchingtarget layer, the method comprising: anisotropically etching the etchingtarget layer through the opening; and forming a film on an inner surfaceof the opening after performing the etching of the etching target layer,wherein, in the anisotropically etching of the etching target layer,plasma of a first gas is generated within a processing vessel of aplasma processing apparatus in which the target object is accommodated,in the forming of the film, the film is formed on the inner surface ofthe opening by repeating a sequence comprising: a first process ofsupplying a second gas into the processing vessel; a second process ofpurging a space within the processing vessel after the first process; athird process of generating plasma of a third gas containing an oxygenatom within the processing vessel after the second process; and a fourthprocess of purging the space within the processing vessel after thethird process, wherein the first gas contains a carbon atom and afluorine atom, the second gas contains an organic-containingaminosilane-based gas, the etching target layer is a hydrophilicinsulating layer containing silicon, and plasma of the first gas is notgenerated in the first process.
 2. The method of claim 1, wherein, inthe first process, the etching target layer is etched through theopening while a temperature of the target object is adjusted to beuniform across regions of the target object.
 3. The method of claim 1,wherein the processing vessel is provided with a first gas inlet openingand a second gas inlet opening, the first gas inlet opening is providedabove the target object, the second gas inlet opening is provided at aside of the target object, in the anisotropically etching of the etchingtarget layer, the first gas is supplied into the processing vessel fromthe first gas inlet opening and a backflow prevention gas is suppliedinto the processing vessel from the second gas inlet opening, in thefirst process, the second gas is supplied into the processing vesselfrom the second gas inlet opening and the backflow prevention gas issupplied into the processing vessel from the first gas inlet opening, inthe third process, the third gas is supplied into the processing vesselfrom the first gas inlet opening and the backflow prevention gas issupplied into the processing vessel from the second gas inlet opening,and a pipeline connected to the first gas inlet opening and a pipelineconnected to the second gas inlet opening are not intersected with eachother.
 4. The method of claim 1, wherein the first gas includes afluorocarbon-based gas.
 5. The method of claim 1, wherein the second gasincludes monoaminosilane.
 6. The method of claim 1, wherein theaminosilane-based gas contained in the second gas includes aminosilanehaving 1 to 3 silicon atoms.
 7. The method of claim 1, wherein theaminosilane-based gas contained in the second gas includes aminosilanehaving one to three amino groups.
 8. A method of processing a targetobject, comprising: selectively forming a first film on a surface of thetarget object; and forming a second film on the surface of the targetobject by atomic layer deposition while removing the first film.
 9. Themethod of claim 8, wherein the deposition includes a sequencecomprising: a first process of supplying a second gas into a processingvessel to form an adsorption layer on the surface of the target object;a second process of purging a space within the processing vessel; and athird process of generating plasma of a third gas within the processingvessel.
 10. The method of claim 9, wherein the deposition furthercomprises a fourth process of exposing the second film to an inert gasplasma after the third process.
 11. The method of claim 9, wherein, inthe forming of the second film, the first film is removed through thethird process or the fourth process.
 12. The method of claim 9, whereinthe second gas is any of an aminosilane-based gas, a silicon-containinggas, a titanium-containing gas, a hafnium-containing gas, atantalum-containing gas, a zirconium-containing gas and anorganic-containing gas, and the third gas is any of an oxygen-containinggas, a nitrogen-containing gas and a hydrogen-containing gas.
 13. Themethod of claim 8, wherein the first film is formed by plasma etching.14. The method of claim 13, wherein the plasma etching is atomic layeretching.
 15. A method of processing a target object, comprising:preparing a target object having a first region made of a first materialand a second region made of a second material different from the firstmaterial; forming a first gas into plasma to etch the first region,thereby forming a first film on the second region; and forming a secondfilm on the first region by atomic layer deposition while removing thefirst film.
 16. The method of claim 15, wherein the first gas includes afluorocarbon gas, the first material includes silicon and oxygen, andthe second material includes any of silicon, an organic material and ametal.
 17. The method of claim 15, wherein the first gas includes afluorohydrocarbon gas, the first material includes silicon and nitrogen,and the second material includes any of silicon, an organic material anda metal.
 18. The method of claim 8, wherein the second film containssilicon.
 19. The method of claim 8, wherein the second film formed onthe target object has multiple film thicknesses.
 20. The method of claim9, wherein, by repeating the sequence, the first film is removed and thesecond film is formed on the surface of the target object from which thefirst film is removed.